A vibration control device for railroad vehicle is known to be interposed between a vehicle body and a truck of a railroad vehicle and suppress vibration which acts on the railroad vehicle in a lateral direction with respect to a moving direction of the vehicle body.
JP2010-65797A discloses a vibration control device for railroad vehicle. This vibration control device for railroad vehicle includes a cylinder coupled to one of a truck and a vehicle body of a railroad vehicle, a piston slidably inserted in the cylinder, a rod inserted in the cylinder and coupled to the piston and the other of the truck and the vehicle body, a rod-side chamber and a piston-side chamber partitioned in the cylinder by the piston, a tank, a first on-off valve disposed at an intermediate position of a first passage communicating between the rod-side chamber and the piston-side chamber, a second on-off valve disposed at an intermediate position of a second passage communicating between the piston-side chamber and the tank, a pump for supplying hydraulic oil to the rod-side chamber, a discharge passage connecting the rod-side chamber to the tank and a variable relief valve disposed at an intermediate position of the discharge passage and capable of changing a valve opening pressure.
This vibration control device for railroad vehicle generates a thrust force in both extension and contraction directions and suppresses the vibration of the vehicle body with this thrust force by driving the pump, the first and second on-off valves and the variable relief valve.